Pulseless electrical activity (PEA) also referred to as electromechanical dissociation (EMD), has been described as "the presence of organized electrical activity on the electrocardiogram but without palpable pulses." It is the common end-point for a number of processes that interfere with cardiopulmonary function, in particular major cardiac insults and respiratory failure with hypoxia. The vast majority of patients suffering PEA in the out-of-hospital setting will not survive. Therefore, an effective treatment for PEA could be extraordinarily important. Previous research has demonstrated that a large fraction of patients in PEA actually have residual cardiac mechanical activity. The research team has developed a hypothesis that outcomes may improve if cardiac compressions are synchronized with residual myocardial mechanical activity. In other words, we hypothesize that outcomes will improve if compressions are timed to assist ejection -- squeezing the chest during intrinsic contractions -- and relaxing so as to allow adequate ventricular filling during intrinsic diastole. In response to NIH Program Announcement (PA) 04-059 - Technologies for Monitoring and Performing Resuscitation, Rose Biomedical Development Corporation proposes to develop and pilot test Cardiac Synchronization Technology (CST), a non-invasive approach to improving outcomes by synchronizing chest compression with residual cardiac mechanical activity in patients with pseudo-EMD PEA. [unreadable] [unreadable] [unreadable]